The present invention relates to a pressure equalizer for use at deep sea as a pressure equalization or gas supply system.
When a vessel filled with a gas is to be dropped to the deep sea for installation of the vessel at a sea bed, the vessel itself is made pressure resistant to withstand a high pressure at the deep sea.
Such pressure resistance of the vessel is conventionally attained by increasing a wall thickness of the the pressure vessel. The increase of the wall thickness of the vessel for enhancement of mechanical strength of the same might be averted by using materials such as titanium, which is very expensive. However, a relatively large pressure vessel could not be constructed from titanium, which has poor machinability.
In view of the above, a primary object of the present invention is to provide a pressure equalizer for use at a deep sea which can equalize internal and external pressures of a vessel, whereby the vessel can be used at the deep sea without increasing the wall thickness of the vessel for the purpose of enhancing the mechanical strength of the vessel.